Optical imaging system

Abstract

An optical imaging system includes a first lens having refractive power, a second lens having refractive power and having a convex object-side surface, a third lens having refractive power and having a convex object-side surface, a fourth lens having refractive power, a fifth lens having refractive power, and a sixth lens having negative refractive power. The optical imaging system satisfies 100°≤FOV, and −2.0<{IMGHT/(f*tan(FOV/2))−1}*100<2.0, where FOV is a field of view of the optical imaging system, IMGHT is half of a diagonal length of an imaging plane, and f is a focal length of the optical imaging system.

What is claimed is: 
     
         1 . An optical imaging system comprising:
 a first lens having refractive power;   a second lens having refractive power and having a convex object-side surface;   a third lens having refractive power and having a convex object-side surface;   a fourth lens having refractive power;   a fifth lens having refractive power; and   a sixth lens having negative refractive power,   wherein the first to sixth lenses are disposed in order from an object side, and   wherein
   1000≤FOV
 
   −2.0<{IMGHT/( f *tan(FOV/2))−1}*100<2.0,
 
   where FOV is a field of view of the optical imaging system, IMGHT is half of a diagonal length of an imaging plane, and f is a focal length of the optical imaging system.   
     
     
         2 . The optical imaging system of  claim 1 , wherein the first lens has a concave object-side surface or a concave image-side surface. 
     
     
         3 . The optical imaging system of  claim 1 , wherein the fourth lens has a concave object-side surface. 
     
     
         4 . The optical imaging system of  claim 1 , wherein the fifth lens has a convex object-side surface or a convex image-side surface. 
     
     
         5 . The optical imaging system of  claim 1 , wherein the sixth lens has a convex object-side surface. 
     
     
         6 . The optical imaging system of  claim 1 , wherein the sixth lens has a concave image-side surface. 
     
     
         7 . The optical imaging system of  claim 1 , wherein
   −1.5< f 3/ f 4<−0.7,
   where f3 is a focal length of the third lens, and f4 is a focal length of the fourth lens.   
     
     
         8 . The optical imaging system of  claim 1 , wherein
   0.6<| f 4/ f 6|<1.8,   where f4 is a focal length of the fourth lens, and f6 is a focal length of the sixth lens.   
     
     
         9 . The optical imaging system of  claim 1 , wherein
   1.3< TTL /IMGHT<1.4,   where TTL is a distance from the object-side surface of the first lens to the imaging plane.   
     
     
         10 . The optical imaging system of  claim 1 , wherein
   1.8< f  number<2.3.   
     
     
         11 . An optical imaging system comprising:
 a first lens having refractive power;   a second lens having refractive power and having a convex object-side surface;   a third lens having refractive power and having a convex object-side surface;   a fourth lens having refractive power;   a fifth lens having refractive power; and   a sixth lens having refractive power,   wherein the first to sixth lenses are disposed in order from an object side, and   wherein
   1000≤FOV,
 
   −2.0<{IMGHT/( f *tan(FOV/2))−1}*100<2.0, and
 
     TTL /IMGHT<1.4, 
   where FOV is a field of view of the optical imaging system, IMGHT is half of a diagonal length of an imaging plane, f is a focal length of the optical imaging system, and TTL is a distance from the object-side surface of the first lens to the imaging plane.   
     
     
         12 . The optical imaging system of  claim 11 , wherein the first lens has refractive power having a sign different from a sign of the refractive power of the second lens. 
     
     
         13 . The optical imaging system of  claim 11 , wherein the fourth lens has refractive power having a sign different from a sign of the refractive power of the fifth lens. 
     
     
         14 . The optical imaging system of  claim 11 , wherein the sixth lens has negative refractive power. 
     
     
         15 . The optical imaging system of  claim 11 , wherein the sixth lens has a convex object-side surface. 
     
     
         16 . The optical imaging system of  claim 11 , wherein
   1.0< f 1/ f 3<3.0,   where f1 is a focal length of the first lens, and f3 is a focal length of the third lens.   
     
     
         17 . The optical imaging system of  claim 11 , wherein
   0.2< f 3/ f 5<2.0,   where f3 is a focal length of the third lens, and f5 is a focal length of the fifth lens.